The University of California at Davis (UCD) is a diverse educational institution recognized for excellence in medical, veterinary and agricultural research. In 1998, the UCD Flow Cytometry Shared Resource Laboratory received S10 program support (S10-RR012964-01) to purchase a multi-laser, 10-color Cytomation MoFlo high- speed cell sorter. Specific features in the design of the MoFlo cell sorter are ideally suite for use in a shared resource lab, facilitating the analysis and sorting of a variety of cells from human and animal tissues, as well as microparticles, microorganisms, and plant cell protoplasts. For 15 years, the MoFlo has supported the research of UCD investigators across a wide range of multidisciplinary programs in Davis and at the UCD Medical Center in Sacramento, including the Schools of Medicine and Veterinary Medicine, NCI Comprehensive Cancer Center and the California National Primate Research Center. However, after years of reliable service, the original legacy MoFlo is now in need of replacement. Key component systems are aged and obsolete, have become unreliable and are expensive or impossible to maintain, particularly the water-cooled gas lasers. Further, the large size of the legacy MoFlo does not allow for enclosure in a biosafety containment cabinet and fails to meet the modern biosafety recommendations of the International Society for the Advancement of Cytometry and the newly approved NIH Biosafety Policy for Cell Sorters. The proposed replacement instrumentation, the Beckman Coulter AstriosEQ, offers modern components but uses the same stable, reliable fluidic design that is the hallmark of MoFlo cell sorters. The AstriosEQ will be equipped with 4 lasers and 16 photodetectors to detect commonly used fluorescent probes and proteins and will be housed in a biosafety containment hood with aerosol management to ensure safe sorting of biohazardous samples. The success of NIH supported biological research at UC Davis depends on the uninterrupted availability of a flexible, reliable, and safe cell sorter. The AstriosEQ willbe housed in, managed and maintained by the Davis campus Shared Flow Cytometry Laboratory so that UCD investigators have access to cell sorting instrumentation and flow cytometry expertise for years to come.